Conversion of arable land (maize) to pasture will affect the soil organic matter (SOM) content. Changes in the SOM content were studied using a size- and density-fractionation method and C-13 analysis. Twenty-six years of maize cropping had resulted in a depletion of carbon stored in the macro-organic fractions (>150 mu m) and an increase in the 250 mu m), light (b.d. 150 mu m) and light (b.d. 150 mu m; b.d. >1.13 g cm(-3)) in the 0- to 20-cm layer was still 40-50% lower than in the continuous pasture plots. Average half-life times calculated from C-13 analyses ranged from 7 years in the light fractions to 56 years in heavy fractions. Fractionation results and C-13 data indicated that mechanical disturbance (plowing) during maize cropping had resulted in vertical displacement of dispersed soil carbon from the 0- to 20-cm layer down to 60-80 cm. Conversion of arable land to pasture, therefore, not only causes a regeneration of the soil carbon content, it also reduces the risk of contaminant transport by dispersed soil carbon.
", "keywords": ["land use change", "DECOMPOSITION", "2. Zero hunger", "C-13 analyses", "04 agricultural and veterinary sciences", "15. Life on land", "maize", "Maize", "C-13 NATURAL-ABUNDANCE", "CULTIVATION", "pasture", "13C analyses", "VERTISOLS", "SIZE", "SYSTEMS", "Pasture", "0401 agriculture", " forestry", " and fisheries", "Organic matter", "Fractionation", "fractionation", "Land use change", "CARBON TURNOVER", "FRACTIONS", "organic matter", "STORAGE"], "contacts": [{"organization": "R\u00f6mkens, P.F.A.M., van der Plicht, J., Hassink, J.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1007/s003740050494"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Biology%20and%20Fertility%20of%20Soils", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s003740050494", "name": "item", "description": "10.1007/s003740050494", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s003740050494"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "1999-01-01T00:00:00Z"}}, {"id": "10.1016/j.geoderma.2004.02.014", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:16:06Z", "type": "Journal Article", "created": "2004-04-10", "title": "Conversion Of Grassy Cerrado Into Riparian Forest And Its Impact On Soil Organic Matter Dynamics In An Oxisol From Southeast Brazil", "description": "Abstract The purpose of this study was to evaluate possible changes in soil organic matter (SOM) dynamics after establishing riparian forests on soils previously under Brazilian savannah (\u201ccerrado\u201d). We selected a site with a homogeneous Typic Acric Red\u2013Yellow Latosol (Anionic Acrustox). Part of this site was maintained under native vegetation (grassy cerrado C 4 -dominated), and part was planted with riparian species (C 3 ) in 1992. Litter and soil samples were collected and analysed (total organic carbon, total nitrogen, \u03b4 13 C isotopic analysis, and SOM density fractionation). Due to the predominance of grasses, carbon input was mainly below ground in cerrado. In such a soil, the decomposition process was more efficient, and much C and N were transferred to the heavy fraction. When forest was planted, there was a change from belowground to aboveground litter input (largely superficial), leading to higher C and N stocks in the light and lower stocks in the heavy fraction (resulting in lower stocks for bulk soil). The introduction of the C 3 vegetation decreased the soil \u03b4 13 C signature. It has occurred particularly in the topsoil (0\u20135 cm) due to the deposition of C 3 litter on the soil surface. At the same time, the presence of cerrado-remaining C below 5 cm maintained higher \u03b4 13 C values in this layer. During the 8 years after forest plantation, the input mode influenced both the \u03b4 13 C distribution with depth, and the C replacement: between 0 and 2.5 cm, nearly 50% of cerrado-derived C was replaced by forest-derived C, while below 5 cm, replacement was around 20%. The relatively rapid C dynamics in this Oxisol (27% replacement in the top 20 cm after 8 years of forest plantation) shows that, under tropical conditions, significant changes may occur in a short period of time.", "keywords": ["delta-c-13", "decomposition", "c-13 natural-abundance", "particle-size fractions", "turnover", "0401 agriculture", " forestry", " and fisheries", "vegetation changes", "04 agricultural and veterinary sciences", "15. Life on land", "stable carbon isotope", "density fractions", "ratios", "nitrogen"], "contacts": [{"organization": "de Alcantara, F.A., Buurman, P., Furtini Neto, A.E., Curi, N., Roscoe, R.,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1016/j.geoderma.2004.02.014"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Geoderma", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.geoderma.2004.02.014", "name": "item", "description": "10.1016/j.geoderma.2004.02.014", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.geoderma.2004.02.014"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2004-12-01T00:00:00Z"}}, {"id": "10.1111/j.1365-2389.2005.00707.x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-04-16T16:18:27Z", "type": "Journal Article", "created": "2005-09-12", "title": "Long-Term Changes In Organic Matter Of Woodland Soils Cleared For Arable Cropping In Zimbabwe", "description": "SummarySubsistence farmers in Africa depend largely on the soil organic matter to sustain crop productivity. Long\uffe2\uff80\uff90term changes in soil organic carbon and nitrogen were measured after woodland clearance for smallholder subsistence farming or for commercial farming. The contents of organic carbon and nitrogen in soil under reference woodlands were largest (53.3\uffe2\uff80\uff83t C ha\uffe2\uff88\uff921, 4.88\uffe2\uff80\uff83t N ha\uffe2\uff88\uff921) in a red clay soil (\uffe2\uff88\uffbc\uffe2\uff80\uff8350% clay + silt), followed by a granitic sand (\uffe2\uff88\uffbc\uffe2\uff80\uff8312% clay + silt; 22.8\uffe2\uff80\uff83t C ha\uffe2\uff88\uff921, 1.47\uffe2\uff80\uff83t N ha\uffe2\uff88\uff921) and least (19.5\uffe2\uff80\uff83t C ha\uffe2\uff88\uff921, 0.88\uffe2\uff80\uff83t N ha\uffe2\uff88\uff921) in a Kalahari sand (\uffe2\uff88\uffbc\uffe2\uff80\uff835% clay + silt). Organic carbon declined rapidly under cultivation to attain new equilibria within 10\uffe2\uff80\uff83years on all smallholdings. Greatest losses occurred in soils that initially contained most carbon and nitrogen in the order: red clay (22.4\uffe2\uff80\uff83t C ha\uffe2\uff88\uff921 and 1.0\uffe2\uff80\uff83t N ha\uffe2\uff88\uff921) > granitic sand (13.2\uffe2\uff80\uff83t C ha\uffe2\uff88\uff921 and 0.8\uffe2\uff80\uff83t N ha\uffe2\uff88\uff921) > Kalahari sand (10.6\uffe2\uff80\uff83t C ha\uffe2\uff88\uff921 and 0.5\uffe2\uff80\uff83t N ha\uffe2\uff88\uff921). On the clay soil, commercial farming with intensive use of mineral fertilizers and incorporation of maize stover led to more gradual decline: at equilibrium, contents of carbon and nitrogen were 15\uffe2\uff80\uff83t C ha\uffe2\uff88\uff921 and 1.7\uffe2\uff80\uff83t N ha\uffe2\uff88\uff921 greater than on smallholdings with similar soil and climate.
In the Kalahari sand the \uffce\uffb413C of organic C remained constant after woodland clearance, and maize contributed less than 10% of the total C even after 55\uffe2\uff80\uff83years. The \uffce\uffb413C signature increased slightly with increasing duration of cultivation by smallholders in the granitic sands and red clay soil where maize contributed 29% and 35% of the C at equilibrium. Under more productive commercial farming, the carbon derived from maize accounted for 50% of the total after 10\uffe2\uff80\uff83years of cultivation and 67% at equilibrium. The persistence of woodland carbon in the sandy soil is attributed to chemical stabilization resulting from large concentrations of lignin and polyphenols in the tree litter, or as charcoal.
", "keywords": ["2. Zero hunger", "agroecosystems", "c-13 natural-abundance", "carbon dynamics", "spodosols", "04 agricultural and veterinary sciences", "15. Life on land", "maize", "stabilization", "residues", "vegetation", "0401 agriculture", " forestry", " and fisheries", "sandy soils", "isotope"], "contacts": [{"organization": "Shamie Zingore, Ken E. Giller, Ken E. Giller, P. Nyamugafata, C. Manyame,", "roles": ["creator"]}]}, "links": [{"href": "https://doi.org/10.1111/j.1365-2389.2005.00707.x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/European%20Journal%20of%20Soil%20Science", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/j.1365-2389.2005.00707.x", "name": "item", "description": "10.1111/j.1365-2389.2005.00707.x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/j.1365-2389.2005.00707.x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2005-04-11T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=C-13+NATURAL-ABUNDANCE&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=C-13+NATURAL-ABUNDANCE&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=C-13+NATURAL-ABUNDANCE&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=C-13+NATURAL-ABUNDANCE&offset=3", "hreflang": "en-US"}], "numberMatched": 3, "numberReturned": 3, "distributedFeatures": [], "timeStamp": "2026-04-17T07:25:16.020781Z"}